Wear resistant structures and components are used e.g. in equipment for reducing the size of rock, building or recycling material. In these processes, the material being crushed, pressed between the components or impacting the surfaces of the structures or components, cause wear on the surfaces of the components to an extent depending on the contact surface pressure, velocities, material characteristics of the component surfaces and on the physical characteristics of the material being crushed, e.g. the compressive strength and tribology characteristics. In other words, the movement of the material being crushed with respect to the surfaces of the components as well as the penetration of the material into the surface of the component have influence on the wear of the component: The material moving with respect to the surfaces of the components causes cutting and grooving, and the material penetrating the surface produces burrs on the affected area, which burrs are easily detached from the surface of the structures and components by breakage, fatigue or formation of cuttings as the events occur repeatedly. The intensity of the wear of the structures and components in their various sections and in the equipment generally is defined by the geometry of the equipment, the motion state of the components and the flow parameters of the material being crushed.
Attempts to increase the effective service life of the structures and components in general are generally made not only by influencing the geometry and internal flow conditions of the equipment, but in particular by selecting advantageous materials. The tribology characteristics of metallic wear protection materials of prior art are based e.g. on advantageous alloying of the relevant metals, and possible addition of particles, on manufacturing processes and further treatments, like heat treatments, whereby phases having better than usual resistance to wear phenomena will be formed in their microstructure as a combined effect of all these factors, said phases typically being hard but often having low toughness and fatigue resistance. As characteristics apart from tribology characteristics are required from the structures and components, they usually cannot be manufactured completely from the materials having the microstructure described above. On the other hand, also the control of the wear pattern of the structures and components, e.g. for maintaining the geometry and internal flow model of the equipment, may require that different portions of the structures and components are manufactured from materials different from each other.
The methods used in manufacturing multimaterial components must almost without exception be adapted according the requirements of all the materials forming the structure, whereby the characteristics achieved in each material fall short of the target level for the respective material, and the best possible performance of the structure or the component will not be reached. Another significant challenge is to maintain the dimensional and shape tolerances of the pieces or portions during assembly and the subsequent treatments, which will be jointly directed to the pieces or portions consisting of various materials and to the boundaries between them. Thereby the different behavior of the materials in contact with or joined to each other, e.g. different volumetric changes, can cause damage to the structures and components. The above mentioned requirements totally exclude a number of manufacturing methods or at least complicate the manufacturing processes unreasonably as far as commercial exploitation is concerned.
In the methods and wear parts in accordance with Patent publications JP5317731, JP5317732 and JP6079187 on the contrary, the aim is to manufacture structures having parts of low durability placed in a wear resistant frame and thus to selectively and locally increase the rate of wear, thereby controlling the surface shape of the wear parts.
In the wear parts disclosed in Patent publication JP2001165146, a material having better wear resistance is introduced for controlling the wear pattern, but only a joining method requiring strict shape and measure tolerances is disclosed for the purpose of manufacturing the desired structures, which in terms of cost-efficiency is not reasonable.
Further, according to patent publication JP7323238 the aim is to directly obtain the functionally most preferred form of wear parts during the assembly of the structures, by mounting exactly formed wear protection pieces to the component bodies, whereby the expensive multi-stage manufacturing process of both the body parts and the wear protection pieces cannot be avoided.
Patent publications JP2001269589 and U.S. Pat. No. 6,123,279 disclose wear parts correspondingly aiming at increasing wear resistance by mounting wear resistant material in the body of the wear part, but by using a geometrically shape-locking joint, which also requires applying technically demanding and cost-increasing design methods to wear protection materials which are difficult to work and shape, e.g. the hard metals according to the latter publication, to achieve the dimensional and shape accuracy required for the assembly.
Patent publication JP2004160360 also discloses, that the wear resistant part must be formed (grooved) in a certain way for joining, which is not technically and economically profitable for the wear resistant materials to be used in the method in accordance with the invention.
Patent publication WO 03/099443 A1 discloses a manufacturing method for multimaterial structures, where wear resistant material or materials are joined to a body part made of machineable material by means of hot isostatic pressing directly using a direct diffusion joint or by using powder material added between the body and the wear resistant pieces. The gas-tight encapsulating of the structure required by the method, and the fact that at least partial machining is generally required for the pieces being joined, increase the work phases of the component manufacturing and increase the manufacturing costs too much for the utilization of the method to be economically profitable.